The OFFICIAL will the conveyor belt plane fly thread!!!! **UPDATE FIRST POST*** - Page 5

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[ARCHIVED THREAD] - The OFFICIAL will the conveyor belt plane fly thread!!!! **UPDATE FIRST POST*** (Page 5 of 20)

Posted: 12/10/2007 9:51:48 PM EDT

[#1]

Little Garrett Says

Shit'll Fly.

utub

Posted: 12/10/2007 9:52:09 PM EDT

[#2]

Quoted:
The origional scenario said the conveyor keeps the airplane from moving foward...so it won't fly

No such conveyor exists, nor could one be constructed. We might as well write:

A purple giraffe jizzes on the runway, and keeps an airplane from moving forward. If the pilot applies full throttle against the giraffe jizz all over the runway, will the airplane fly?

And logically, the answer is no. It won't. Because the problem states that giraffe spooge can prevent an airplane from taking off. Then, a few arfcommers come along and say "WTF? How in the hell is giraffe spooge supposed to keep an airplane from taking off?" And another arfcommer says "Who cares? The problem says that's what happens".

I think I see the disconnect, here.

Posted: 12/10/2007 9:53:42 PM EDT

[#3]

Quoted:

Quoted:

The airplanes wheels would have to rotate in a forward direction in order for the entire airplane to move (it is still on the ground, not in the air). If the conveyor accelerates, the wheels move backwards even faster as the airplane is trying to move forward with the thrust of its engines. There is no relative forward motion and the plane won't fly. the tires just spin fast, the engines spin fast and blast a lot of air out the back that would be accelerating the airplane forward, but the conveyor is keeping it from moving forward at all.

*sigh* And you had it.

The wheels are only going to rotate in one direction. Talking about them rotating forwards or backwards is just confusing you. How fast they rotate has nothing to do with the airplane taking off or not. What matters are the forces involved. The force of the engine is always going to overcome the force of friction of the bearings in the wheels.

-Local

sure the wheels will rotate in a forward (counter-clockwise if looked at from left side of aircraft) motion. they will only rotate forward as the conveyor moves in a clockwise rotation. how fast they rotate does have something to do with it. if the conveyor is turning at the exact same speed as the wheels, the planes fuselage (connected to the wheels through the landing gear) will not move through the air.

That is true, however the question was "can the engines cause the plane to move forward through the air despite the rearward motion of the belt". The answer is, of course yes, because the engines can produce more thrust than the belt can apply drag.

Posted: 12/10/2007 9:54:14 PM EDT

[#4]

Quoted:
Pretty please, answer this question...

Take a Saturn 5 rocket. Strap wheels to it. Place it on the TMC©. Ignite...

Does the rocket move?

Rockets do not need airflow over wings to fly!

Posted: 12/10/2007 9:54:56 PM EDT

[#5]

OK . . . OK . . . maybe I get it.

Sniper7, you are correct. If the wheel speed matches the conveyor belt speed, there will be NO airspeed, and therefore no lift (assuming there's no wind).

What WE are arguing (and indeed, PROVING time and time again) is that while this is true in theory, it is impossible in practice to FORCE this scenario on an aircraft. You could do it, but it would be easy to get out of it. Just add a little more juice to the engines.

Posted: 12/10/2007 9:55:11 PM EDT

[#6]

Quoted:

Quoted:
Pretty please, answer this question...

Take a Saturn 5 rocket. Strap wheels to it. Place it on the TMC©. Ignite...

Does the rocket move?

Rockets do not need airflow over wings to fly!

Thats not an answer...

Posted: 12/10/2007 9:55:39 PM EDT

[#7]

Quoted:

Quoted:
Pretty please, answer this question...

Take a Saturn 5 rocket. Strap wheels to it. Place it on the TMC©. Ignite...

Does the rocket move?

Rockets do not need airflow over wings to fly!

But how is airflow in any way connected to the conveyor belt?

Posted: 12/10/2007 9:55:50 PM EDT

[#8]

Quoted:

Quoted:
The origional scenario said the conveyor keeps the airplane from moving foward...so it won't fly

No such conveyor exists, nor could one be constructed. We might as well write:

A purple giraffe jizzes on the runway, and keeps an airplane from moving forward. If the pilot applies full throttle against the giraffe jizz all over the runway, will the airplane fly?
.

But is the giraffe DNA dressing purple as well?

Posted: 12/10/2007 9:56:07 PM EDT

[#9]

Quoted:
OK . . . OK . . . maybe I get it.

Sniper7, you are correct. If the wheel speed matches the conveyor belt speed, there will be NO airspeed, and therefore no lift (assuming there's no wind).

What WE are arguing (and indeed, PROVING time and time again) is that while this is true in theory, it is impossible in practice.

Now you are going backwards...

Posted: 12/10/2007 9:56:53 PM EDT

[#10]

Quoted:
OK . . . OK . . . maybe I get it.

Sniper7, you are correct. If the wheel speed matches the conveyor belt speed, there will be NO airspeed, and therefore no lift (assuming there's no wind).

What WE are arguing (and indeed, PROVING time and time again) is that while this is true in theory, it is impossible in practice.

Let's not get off track now!!! The wheel speed will ALWAYS match the conveyor belt speed. This has nothing to do with airspeed....nothing, not at all.

Posted: 12/10/2007 9:56:53 PM EDT

[#11]

Quoted:
OK . . . OK . . . maybe I get it.

Sniper7, you are correct. If the wheel speed matches the conveyor belt speed, there will be NO airspeed, and therefore no lift (assuming there's no wind).

What WE are arguing (and indeed, PROVING time and time again) is that while this is true in theory, it is impossible in practice.

Even that's not quite right. AeroE will be along shortly to discuss tangential vs angular velocity of the wheels.

I thought we could avoid that part.

Posted: 12/10/2007 9:57:39 PM EDT

[#12]

Quoted:

Quoted:
OK . . . OK . . . maybe I get it.

Sniper7, you are correct. If the wheel speed matches the conveyor belt speed, there will be NO airspeed, and therefore no lift (assuming there's no wind).

What WE are arguing (and indeed, PROVING time and time again) is that while this is true in theory, it is impossible in practice.

Now you are going backwards...

Huh?

It is true that if the belt speed matches the wheel speed, the plane will be stationary.

But that's as far as it goes.

Posted: 12/10/2007 9:58:28 PM EDT

[#13]

Quoted:
OK . . . OK . . . maybe I get it.

Sniper7, you are correct. If the wheel speed matches the conveyor belt speed, there will be NO airspeed, and therefore no lift (assuming there's no wind).

What WE are arguing (and indeed, PROVING time and time again) is that while this is true in theory, it is impossible in practice to FORCE this scenario on an aircraft. You could do it, but it would be easy to get out of it. Just add a little more juice to the engines.

The only way the wheel speed matches the conveyor belt speed is if the plane is not moving. If the plane is not moving, then the conveyor belt shall not move, either.

The wheels will always move at a speed double the speed they should be going at whatever speed the plane is moving forward.

Posted: 12/10/2007 9:58:49 PM EDT

[#14]

Quoted:

Quoted:
OK . . . OK . . . maybe I get it.

Sniper7, you are correct. If the wheel speed matches the conveyor belt speed, there will be NO airspeed, and therefore no lift (assuming there's no wind).

What WE are arguing (and indeed, PROVING time and time again) is that while this is true in theory, it is impossible in practice.

Now you are going backwards...

Huh?

It is true that if the belt speed matches the wheel speed, the plane will be stationary.

But that's as far as it goes.

God Damnit....NO!!!! The belt speed will ALWAYS match the wheel speed...ALWAYS. but whether the two are turning at 10 knots or 1000 has nothing to do with the engines pushing the plane through the air.

Posted: 12/10/2007 9:59:21 PM EDT

[#15]

Quoted:

Quoted:
Is this it? Has the one lone hold out been converted? Have we finally reached a point where every person agrees that the plane will fly? If so, my life is complete. There is nothing left to do. I shall die a happy man.

And we did it without arguing over whether the wheel speed being referenced was tangential or angular.

We've come a long way. The forum is getting smarter by the day. I can feel it.

not converted at all. it won't fly.

Is it because you think a conveyor could actually be devised, that was capable of holding an airplane at full throttle in one place?

why not, in yours and several others worlds, you seem to think an airplane will fly without airflow over the wings because it has no forward motion.

so yes, theoretically, there is a converyor with unlimited speed and we have the best tehcnology of todays commerical aircraft. Take a aircraft with a total thrust capability of 100K lbs of thrust. That equates to mach .80 or so in cruise flight. it is capable of doing 340 knots at around 10000 before hitting the speed tape.
on the ground it is easily capable of reaching speeds (with enough runway) to blow the tires clean off). the conveyor belt is equally as capable on the ground of producing these speeds in the opposite direction.
the pilots spool the engines to takeoff power (full 100K of thrust total) and the conveyor accelerates the same speed keeping the airplane in the same spot. (looked at from the side, there is no forward or backwards relative motion). the tires are spinning at 200 knots and because of such good design do no blow. the plane is using all its power, the conveyor is working opposite it. the wheels are spinning freely. the engines are ripping up pavement behind the airplane, but the plane doesn't fly.

Why?

there is no wind over the wings. there is no differential in pressure. there is no low pressure on the top of the wing, there is no high pressure on the bottom of the wing. there is no airflow over any of the control surfaces. nothing happens.

there is the scenario. now does it fly???

Posted: 12/10/2007 10:00:41 PM EDT

[#16]

Quoted:

Quoted:

The origional scenario said the conveyor keeps the airplane from moving foward...so it won't fly

No you're just adding shit to it because it never said that... It said TMC© would match the wheel speed. Big difference. But I think you already knew that.

okay, so it matches wheel speed. read my above post. conveyor matches wheel speed with engines fully spooled and no excess thrust. plane ain't going nowhere

Posted: 12/10/2007 10:01:41 PM EDT

[#17]

This is the problem as I recieved it in an email.

A plane is standing on a runway that can move (some sort of band conveyer). The plane moves in one direction, while the conveyer moves in the opposite direction. This conveyer has a control system that tracks the plane speed and tunes the speed of the conveyer to be exactly the same (but in the opposite direction).

The question is:

Will the plane take off or not? Will it be able to run up and take off?

I read that to mean that the conveyor belt will run at a linear speed equal to that of the aircraft. So, if the aircraft is moving at 10 mph, then the track will move at exactly 10 miles of track per hour in the other direction.

This does not mean that the aircraft is held motionless. It means that the wheels will spin at twice the RPM as they would otherwise, but the aircraft will keep on moving forward at 10mph or continue to accelerate or whatever it damn well pleases.

Now, if the problem was worded thusly

A plane is standing on a runway that can move (some sort of band conveyer). The plane moves in one direction, while the conveyer moves in the opposite direction. This conveyer has a control system that tracts the thrust of the aircraft and tunes the speed of the conveyer to be exactly that required to keep the airplane motionless by generating friction in the bearings in the landing gear system that precisely overcomes the thrust of the aircraft. We assume that the wheels, bearings and belt can all move at what ever speed needed with out failing from heat, wear etc.

The question is:

Will the plane take off or not? Will it be able to run up and take off?

With that wording, then yes, the airplane could be held stationary. Of course at that point we're suspending so much of the physics involved that it's a pretty pointless question. It might as well be about dragons and fairies on a conveyor belt.

If we use that f15 I like so much, we have to spin those bearings so fast that they generate enough friction to resist thirty thousand pounds of force. With out doing the math I can already tell you that the heat generated would immolate the bearings, wheels, landing struts, track and anything else in the vicinity. And thats assuming that the bearings, wheels and track wouldn't have long since come apart.

But, like I said, as worded, the airplane is taking off.

Posted: 12/10/2007 10:02:02 PM EDT

[#18]

Quoted:

Quoted:

The plane will move forward just as fast as if it was sitting on an airfield...the wheels will simply be spun faster than normal.

There is one concept that you are seriously failing to see:

The movement of the conveyor is dependent upon the speed of the aircrafy. In order for the conveyor to "match the speed" of the plane, the plane must be moving. It will not appear stationary - it will be moving forward at X speed, but the wheels will be spinning at 2X speed.

How hard is this to understand? The conveyor does NOT MOVE unless the plane moves..

but you are still on the ground. sure the wheels aren't needed in the air, but they are needed on the ground. ever see a 747 taxi with its gear up? didn't think so. needs the tires to reduce friction. the plane moves forward because the thrust is the power source...sure that easy to understand, but the reason it moves forward easily is due to the tires having a small coefficent of friction compared to the aluminum fuselage of the plane. the tires have to spin forward at a certain rate (if there is no wind whatsoever) in order for the plane to generate forward movement. the forward movement is read in airspeed. at a certain airspeed, the plane will take off. and the tires will be rotating at same groundspeed (no coveyor belt, plane at sea level on a standard day).

the air over the wings generates the lift. more lbs of lift is created over the weight of the aircraft in lbs and off she goes into the air.

if, in your scenario, there is no relative movement of the airplane at all, it won't fly. there is no headwind, the airplane has no forward motion. won't get off the ground.

if your converyor belt sucks and allows the airplane to move foward, all you are doing is requiring more wheel rotations (which will blow the tires depending on their rating)

If you have -10 knots of groundspeed from your conveyor and the airplane needs to rotate and 140 knots. the plane has to be doing 140 knots of airspeed. this translates into 150 knots of wheel speed AKA: groundspeed. on my airplane, 182 knots is max groundspeed for the wheels. above that, a very high chance of a blowout occurs.

headwind or tailwind is not considered in this situation.

The conveyor belt will not stop the plane. You can get the best damned conveyor belt in the world and it will not stop the plane from moving forward, it will only cause the wheels to spin faster.

Read the big red part again.

read the red part. the entire scenario is pointless. all you are saying is that it takes forward motion and forward wheel speed (whether 2x great or 3x greater or whatever) over the conveyor belts speed in order for the plane to reach sufficient forward speed to generate the lift required.

Even the cars come into play on this then. a conveyor is moving backwards at 10 mph. the car accelerates to mph on the speedo. it is doing 10 mph through the air, 20 over the ground.

same with the airplane. 10 knots backwards on the conveyor, 20 knots airspeed, the plane is moving forward at 10 knots of airspeed, 20 knots groundspeed.

The origional scenario said the conveyor keeps the airplane from moving foward...so it won't fly

DING DING DING....close this thread. You misunderstood the original scenario because IT IS IMPOSSIBLE for the converyor to keep the plane from moving forward. That's the question the original scenario posed in the first place...."Can the conveyor keep the airplane from flying". The answer, of course, is no. You've been trying to answer the wrong question.

ding ding ding....what about if the engines were at full power and the conveyor kept the airplane from moving foward at all??? ding ding ding it won't fly.

Posted: 12/10/2007 10:02:25 PM EDT

[#19]

Quoted:

Quoted:
Is this it? Has the one lone hold out been converted? Have we finally reached a point where every person agrees that the plane will fly? If so, my life is complete. There is nothing left to do. I shall die a happy man.

And we did it without arguing over whether the wheel speed being referenced was tangential or angular.

We've come a long way. The forum is getting smarter by the day. I can feel it.

not converted at all. it won't fly.

Is it because you think a conveyor could actually be devised, that was capable of holding an airplane at full throttle in one place?

why not, in yours and several others worlds, you seem to think an airplane will fly without airflow over the wings because it has no forward motion.

so yes, theoretically, there is a converyor with unlimited speed and we have the best tehcnology of todays commerical aircraft. Take a aircraft with a total thrust capability of 100K lbs of thrust. That equates to mach .80 or so in cruise flight. it is capable of doing 340 knots at around 10000 before hitting the speed tape.
on the ground it is easily capable of reaching speeds (with enough runway) to blow the tires clean off). the conveyor belt is equally as capable on the ground of producing these speeds in the opposite direction.
the pilots spool the engines to takeoff power (full 100K of thrust total) and the conveyor accelerates the same speed keeping the airplane in the same spot. (looked at from the side, there is no forward or backwards relative motion). the tires are spinning at 200 knots and because of such good design do no blow. the plane is using all its power, the conveyor is working opposite it. the wheels are spinning freely. the engines are ripping up pavement behind the airplane, but the plane doesn't fly.

Why?

there is no wind over the wings. there is no differential in pressure. there is no low pressure on the top of the wing, there is no high pressure on the bottom of the wing. there is no airflow over any of the control surfaces. nothing happens.

there is the scenario. now does it fly???

Holy flaming shit-balls man....once again...what does the ground speed (i.e. wheel speed) have to do with engine thrust against the air? They are two totally separate systems from one another.

Posted: 12/10/2007 10:02:53 PM EDT

[#20]

Quoted:
OK . . . OK . . . maybe I get it.

Sniper7, you are correct. If the wheel speed matches the conveyor belt speed, there will be NO airspeed, and therefore no lift (assuming there's no wind).

What WE are arguing (and indeed, PROVING time and time again) is that while this is true in theory, it is impossible in practice to FORCE this scenario on an aircraft. You could do it, but it would be easy to get out of it. Just add a little more juice to the engines.

I have to add something. Assuming the wheel treads are good and the runway/conveyor belt isn't too slick or anything, the tengental velocity of the wheels will match the velocity of the conveyor belt. No matter whether the plane has positive, negative, or neutral airspeed! Yessssss, indeedy! Believe it or not!

If the belt is moving backwards at 30mph and you're moving forwards at 30mph, your groundspeed in relation to the belt is 60mph, and the edges of the wheels are spinning at 60mph too! If you slow down to 30mph, you're now stationary to the ground, the wheels are spinning at 30mph, and your groundspeed in relation to the belt is 30mph!

Posted: 12/10/2007 10:03:06 PM EDT

[#21]

Quoted:
OK . . . OK . . . maybe I get it.

Sniper7, you are correct. If the wheel speed matches the conveyor belt speed, there will be NO airspeed, and therefore no lift (assuming there's no wind).

What WE are arguing (and indeed, PROVING time and time again) is that while this is true in theory, it is impossible in practice to FORCE this scenario on an aircraft. You could do it, but it would be easy to get out of it. Just add a little more juice to the engines.

wheel speed is not related to air speed in any way shape or form, period, ever. not in this example, and not in real life.

take a real life example. an airplane's nose is pointed into a 20kt wind. It has an automatic airspeed of 20kts right there with zero ground speed because there is 20kts of wind moving over the wings.

Now say that it attempts to take off. It needs 100kts of airspeed to take off. With a 20kt headwind that means it only needs 80kts of additional airspeed to takeoff, so when it lifts off the ground, it will only be moving at 80kts over the ground, but will still have 100kts moving over the wings. This is why airplanes always takeoff and land into the wind, and not with it.

Now translate that to wheel speed. Say on a calm wind day the wheels spin at 1000rpm at the moment of liftoff. Now on a 20kt headwind day the airplane only needs 80kts groundspeed to attain its 100kt airspeed for takeoff. That's 20% less groundspeed required, so the wheels will only spin at 800rpm.

Wheels spin at a rate equal to the ground passing underneath the airplane. It has NOTHING to do with the movement of air. The airplane's engines move the airplane completely independently of the the airplane's motion relative to the ground.

The wheels will spin faster, but the airplane will still attain its requisite airspeed by pushing air behind it as normal, and will still take off.

Posted: 12/10/2007 10:04:21 PM EDT

[#22]

Quoted:
OK . . . OK . . . maybe I get it.

Sniper7, you are correct. If the wheel speed matches the conveyor belt speed, there will be NO airspeed, and therefore no lift (assuming there's no wind).

What WE are arguing (and indeed, PROVING time and time again) is that while this is true in theory, it is impossible in practice to FORCE this scenario on an aircraft. You could do it, but it would be easy to get out of it. Just add a little more juice to the engines.

and if all the power is already being used??

Posted: 12/10/2007 10:04:32 PM EDT

[#23]

Quoted:

Quoted:

The plane will move forward just as fast as if it was sitting on an airfield...the wheels will simply be spun faster than normal.

There is one concept that you are seriously failing to see:

The movement of the conveyor is dependent upon the speed of the aircrafy. In order for the conveyor to "match the speed" of the plane, the plane must be moving. It will not appear stationary - it will be moving forward at X speed, but the wheels will be spinning at 2X speed.

How hard is this to understand? The conveyor does NOT MOVE unless the plane moves..

but you are still on the ground. sure the wheels aren't needed in the air, but they are needed on the ground. ever see a 747 taxi with its gear up? didn't think so. needs the tires to reduce friction. the plane moves forward because the thrust is the power source...sure that easy to understand, but the reason it moves forward easily is due to the tires having a small coefficent of friction compared to the aluminum fuselage of the plane. the tires have to spin forward at a certain rate (if there is no wind whatsoever) in order for the plane to generate forward movement. the forward movement is read in airspeed. at a certain airspeed, the plane will take off. and the tires will be rotating at same groundspeed (no coveyor belt, plane at sea level on a standard day).

the air over the wings generates the lift. more lbs of lift is created over the weight of the aircraft in lbs and off she goes into the air.

if, in your scenario, there is no relative movement of the airplane at all, it won't fly. there is no headwind, the airplane has no forward motion. won't get off the ground.

if your converyor belt sucks and allows the airplane to move foward, all you are doing is requiring more wheel rotations (which will blow the tires depending on their rating)

If you have -10 knots of groundspeed from your conveyor and the airplane needs to rotate and 140 knots. the plane has to be doing 140 knots of airspeed. this translates into 150 knots of wheel speed AKA: groundspeed. on my airplane, 182 knots is max groundspeed for the wheels. above that, a very high chance of a blowout occurs.

headwind or tailwind is not considered in this situation.

The conveyor belt will not stop the plane. You can get the best damned conveyor belt in the world and it will not stop the plane from moving forward, it will only cause the wheels to spin faster.

Read the big red part again.

read the red part. the entire scenario is pointless. all you are saying is that it takes forward motion and forward wheel speed (whether 2x great or 3x greater or whatever) over the conveyor belts speed in order for the plane to reach sufficient forward speed to generate the lift required.

Even the cars come into play on this then. a conveyor is moving backwards at 10 mph. the car accelerates to mph on the speedo. it is doing 10 mph through the air, 20 over the ground.

same with the airplane. 10 knots backwards on the conveyor, 20 knots airspeed, the plane is moving forward at 10 knots of airspeed, 20 knots groundspeed.

The origional scenario said the conveyor keeps the airplane from moving foward...so it won't fly

DING DING DING....close this thread. You misunderstood the original scenario because IT IS IMPOSSIBLE for the converyor to keep the plane from moving forward. That's the question the original scenario posed in the first place...."Can the conveyor keep the airplane from flying". The answer, of course, is no. You've been trying to answer the wrong question.

ding ding ding....what about if the engines were at full power and the conveyor kept the airplane from moving foward at all??? ding ding ding it won't fly.

And for the last fucking time...how would it do that? The video of the kid with plane on the treadmill proves that regardless of how fast the belt is moving, the plane still accelerates forward through the air at the same speed. Why? Because the rearward force on the plane is negated by the wheels spinning freely (i.e. they are preventing the rearward motion of the belt from being transferred to the airframe.

Posted: 12/10/2007 10:04:55 PM EDT

[#24]

Quoted:

Quoted:
OK . . . OK . . . maybe I get it.

Sniper7, you are correct. If the wheel speed matches the conveyor belt speed, there will be NO airspeed, and therefore no lift (assuming there's no wind).

What WE are arguing (and indeed, PROVING time and time again) is that while this is true in theory, it is impossible in practice.

Now you are going backwards...

and you are all learning

Posted: 12/10/2007 10:04:56 PM EDT

[#25]

Quoted:

Quoted:

The origional scenario said the conveyor keeps the airplane from moving foward...so it won't fly

No you're just adding shit to it because it never said that... It said TMC© would match the wheel speed. Big difference. But I think you already knew that.

okay, so it matches wheel speed. read my above post. conveyor matches wheel speed with engines fully spooled and no excess thrust. plane ain't going nowhere

So answer my question about the Saturn 5...

Posted: 12/10/2007 10:05:03 PM EDT

[#26]

Quoted:
ding ding ding....what about if the engines were at full power and the conveyor kept the airplane from moving foward at all??? ding ding ding it won't fly.

OK, fine, I'll ask AGAIN. WHAT GODDAMN FORCE IS KEEPING THE PLANE FROM MOVING FORWARD? And don't goddamned answer "the goddamn conveyor belt!" That is not a goddamned force. Give me a measurable goddamned force that is keeping the goddamned plane from moving goddamned forward.

Posted: 12/10/2007 10:05:21 PM EDT

[#27]

Quoted:

Quoted:
Pretty please, answer this question...

Take a Saturn 5 rocket. Strap wheels to it. Place it on the TMC©. Ignite...

Does the rocket move?

Rockets do not need airflow over wings to fly!

But how is airflow in any way connected to the conveyor belt?

Answer me this! If this theoretical treadmill does indeed work, why is that no military has a super secret squirrel tactical highspeed multicam colored jet fighter treadmill launcher? There are people smarter than you and I in the aerospace engineering field and you mean to tell me that they have not come up with it if it was possible? Case closed!

Posted: 12/10/2007 10:05:35 PM EDT

[#28]

Quoted:

Quoted:
OK . . . OK . . . maybe I get it.

Sniper7, you are correct. If the wheel speed matches the conveyor belt speed, there will be NO airspeed, and therefore no lift (assuming there's no wind).

What WE are arguing (and indeed, PROVING time and time again) is that while this is true in theory, it is impossible in practice.

Let's not get off track now!!! The wheel speed will ALWAYS match the conveyor belt speed. This has nothing to do with airspeed....nothing, not at all.

has everything to do with it. the wheel speed matches the conveyor belt speed. that means no airspeed. that means no flight. very simple

Posted: 12/10/2007 10:06:24 PM EDT

[#29]

Quoted:

Quoted:
OK . . . OK . . . maybe I get it.

Sniper7, you are correct. If the wheel speed matches the conveyor belt speed, there will be NO airspeed, and therefore no lift (assuming there's no wind).

What WE are arguing (and indeed, PROVING time and time again) is that while this is true in theory, it is impossible in practice.

Now you are going backwards...

and you are all learning

The only thing we are learning is how to properly execute a antagonistic troll...

Posted: 12/10/2007 10:07:32 PM EDT

[#30]

Quoted:

Quoted:
OK . . . OK . . . maybe I get it.

Sniper7, you are correct. If the wheel speed matches the conveyor belt speed, there will be NO airspeed, and therefore no lift (assuming there's no wind).

What WE are arguing (and indeed, PROVING time and time again) is that while this is true in theory, it is impossible in practice.

Let's not get off track now!!! The wheel speed will ALWAYS match the conveyor belt speed. This has nothing to do with airspeed....nothing, not at all.

has everything to do with it. the wheel speed matches the conveyor belt speed. that means no airspeed. that means no flight. very simple

OK, I'm calm now. I'll ask very nicely. Kind sir, mayhap you would tell explain to us precisely what force it is that is restricting movement of the aircraft relative to the ground?

Posted: 12/10/2007 10:07:44 PM EDT

[#31]

Quoted:

Quoted:
OK . . . OK . . . maybe I get it.

Sniper7, you are correct. If the wheel speed matches the conveyor belt speed, there will be NO airspeed, and therefore no lift (assuming there's no wind).

What WE are arguing (and indeed, PROVING time and time again) is that while this is true in theory, it is impossible in practice to FORCE this scenario on an aircraft. You could do it, but it would be easy to get out of it. Just add a little more juice to the engines.

The only way the wheel speed matches the conveyor belt speed is if the plane is not moving. If the plane is not moving, then the conveyor belt shall not move, either.

The wheels will always move at a speed double the speed they should be going at whatever speed the plane is moving forward.

your math doesn't add up.
the wheels can be speeding at 100 knots if the conveyor is turning at 100 knots. the plane isn't moving through the air is it? the wheels do 120 and the conveyor does 120, moving yet? i think not. engines are at full thrust now and wheels are turning at 160 and the conveyor is turning at 160. the wheels have no excess speed, the engines have no excess thrust, the airplane in not moving at any speed through the air and will not fly.

Posted: 12/10/2007 10:08:04 PM EDT

[#32]

Quoted:

Answer me this! If this theoretical treadmill does indeed work, why is that no military has a super secret squirrel tactical highspeed multicam colored jet fighter treadmill launcher? There are people smarter than you and I in the aerospace engineering field and you mean to tell me that they have not come up with it if it was possible? Case closed!

It's puff, puff, pass, because you must be high

Posted: 12/10/2007 10:08:14 PM EDT

[#33]

Quoted:

Quoted:
OK . . . OK . . . maybe I get it.

Sniper7, you are correct. If the wheel speed matches the conveyor belt speed, there will be NO airspeed, and therefore no lift (assuming there's no wind).

What WE are arguing (and indeed, PROVING time and time again) is that while this is true in theory, it is impossible in practice.

Let's not get off track now!!! The wheel speed will ALWAYS match the conveyor belt speed. This has nothing to do with airspeed....nothing, not at all.

has everything to do with it. the wheel speed matches the conveyor belt speed. that means no airspeed. that means no flight. very simple

And this is why you don't get it. You've made the mistake of assuming that the wheel speed matters. It doesn't. The wheels could be moving as fast as you want to suppose, and the aircraft is still going to move forward.

I can tell you why, and I have as have many others. Maybe you could tell me why it won't move forward. Tell me what force is counteracting those thirty thousand pounds of force from my f15.

-Local

Posted: 12/10/2007 10:08:42 PM EDT

[#34]

I have never once said that an airplane will fly without airflow over the wings. I have repeated over and over that for this to occur, the plane would have to be stationary. I have repeated over and over that a conveyor could NOT hold an airplane stationary. It's impossible. Now (for what I hope is the last time), I'll address the one misconception you have:

Quoted:
The conveyor belt is equally as capable on the ground of producing these speeds in the opposite direction.
the pilots spool the engines to takeoff power (full 100K of thrust total) and the conveyor accelerates the same speed keeping the airplane in the same spot.

If an airplane is capable of reachiny 300knots on the ground, and you place it (at full power) on a conveyor that is moving backwards at 300knots, the plane does NOT remain stationary. It moves forward (tangential wheel speed - relative to a stationary object adjacent to the conveyor) at 300knots. The wheels rotate twice as fast as they normally would.

This does not apply to a car, since a car is powered by it's wheels. If it was a car, it would remain in place.

If you don't agree with this, and you don't understand why (after all we've said), then I'll gracefully bow out. There is nothing more I can possibly say. I can only wonder why you are intentionally being so obtuse.

Posted: 12/10/2007 10:09:57 PM EDT

[#35]

Ok, it took a minute, but I made yall something...

Posted: 12/10/2007 10:10:00 PM EDT

[#36]

sniper7 is either not a pilot, or an idiot, or both. he clearly has ZERO comprehension of how an airplane propels itself, or the forces acting on an airplane in flight.

Posted: 12/10/2007 10:10:06 PM EDT

[#37]

Quoted:

Quoted:
OK . . . OK . . . maybe I get it.

Sniper7, you are correct. If the wheel speed matches the conveyor belt speed, there will be NO airspeed, and therefore no lift (assuming there's no wind).

What WE are arguing (and indeed, PROVING time and time again) is that while this is true in theory, it is impossible in practice.

Let's not get off track now!!! The wheel speed will ALWAYS match the conveyor belt speed. This has nothing to do with airspeed....nothing, not at all.

has everything to do with it. the wheel speed matches the conveyor belt speed. that means no airspeed. that means no flight. very simple

WHAT? Yes, the wheel-speed matches the conveyor speed....that is groundspeed. but the engines are still capable of pushing the plane forward through the air.

Posted: 12/10/2007 10:11:17 PM EDT

[#38]

Quoted:
your math doesn't add up.
the wheels can be speeding at 100 knots if the conveyor is turning at 100 knots. the plane isn't moving through the air is it? the wheels do 120 and the conveyor does 120, moving yet? i think not. engines are at full thrust now and wheels are turning at 160 and the conveyor is turning at 160. the wheels have no excess speed, the engines have no excess thrust, the airplane in not moving at any speed through the air and will not fly.

Yes, if the speeds match, the plane isn't moving relative to the air. Good for you, you have learned that 1=1 and 2=2.

Now perhaps you could explain what there is to keep the plane from going faster. Right now the plane is barely idling, merely having to equal the friction generated from the wheels at 100mph. Add a little more juice, and you move forward. Voila, airspeed!

Posted: 12/10/2007 10:12:10 PM EDT

[#39]

Quoted:
This is the problem as I recieved it in an email.

A plane is standing on a runway that can move (some sort of band conveyer). The plane moves in one direction, while the conveyer moves in the opposite direction. This conveyer has a control system that tracks the plane speed and tunes the speed of the conveyer to be exactly the same (but in the opposite direction).

The question is:

Will the plane take off or not? Will it be able to run up and take off?

I read that to mean that the conveyor belt will run at a linear speed equal to that of the aircraft. So, if the aircraft is moving at 10 mph, then the track will move at exactly 10 miles of track per hour in the other direction.

This does not mean that the aircraft is held motionless. It means that the wheels will spin at twice the RPM as they would otherwise, but the aircraft will keep on moving forward at 10mph or continue to accelerate or whatever it damn well pleases.

Now, if the problem was worded thusly

A plane is standing on a runway that can move (some sort of band conveyer). The plane moves in one direction, while the conveyer moves in the opposite direction. This conveyer has a control system that tracts the thrust of the aircraft and tunes the speed of the conveyer to be exactly that required to keep the airplane motionless by generating friction in the bearings in the landing gear system that precisely overcomes the thrust of the aircraft. We assume that the wheels, bearings and belt can all move at what ever speed needed with out failing from heat, wear etc.

The question is:

Will the plane take off or not? Will it be able to run up and take off?

With that wording, then yes, the airplane could be held stationary. Of course at that point we're suspending so much of the physics involved that it's a pretty pointless question. It might as well be about dragons and fairies on a conveyor belt.

If we use that f15 I like so much, we have to spin those bearings so fast that they generate enough friction to resist thirty thousand pounds of force. With out doing the math I can already tell you that the heat generated would immolate the bearings, wheels, landing struts, track and anything else in the vicinity. And thats assuming that the bearings, wheels and track wouldn't have long since come apart.

But, like I said, as worded, the airplane is taking off.

do the math what is +10 + -10?

0 sound right? that is your speed in your scenario. now put the engines at full throttle. without a conveyor belt, they would turn at say 160 knots. and the plane would move through the air at 160 knots.

now, add the conveyor to the equation. the conveyor is working at -160 knots.

what is +160 + -160?

0 sound right? that is the speed through the air of the airplane. the wheels are doing 160 knots, the conveyor is doing 160 knots in the opposite direction. the engines have no more thrust. the airspeed is 0. the amount of air passing over the wing is 0. the amount of lift that is generated is 0. the airplane won't fly.

Posted: 12/10/2007 10:13:30 PM EDT

[#40]

Quoted:

Quoted:
OK . . . OK . . . maybe I get it.

Sniper7, you are correct. If the wheel speed matches the conveyor belt speed, there will be NO airspeed, and therefore no lift (assuming there's no wind).

What WE are arguing (and indeed, PROVING time and time again) is that while this is true in theory, it is impossible in practice to FORCE this scenario on an aircraft. You could do it, but it would be easy to get out of it. Just add a little more juice to the engines.

The only way the wheel speed matches the conveyor belt speed is if the plane is not moving. If the plane is not moving, then the conveyor belt shall not move, either.

The wheels will always move at a speed double the speed they should be going at whatever speed the plane is moving forward.

your math doesn't add up.
the wheels can be speeding at 100 knots if the conveyor is turning at 100 knots. the plane isn't moving through the air is it? the wheels do 120 and the conveyor does 120, moving yet? i think not. engines are at full thrust now and wheels are turning at 160 and the conveyor is turning at 160. the wheels have no excess speed, the engines have no excess thrust, the airplane in not moving at any speed through the air and will not fly.

Lets go back to remedial math:

Plane moves forward at 100MPH.

If plane moves forward at 100MPH, then the conveyor is moving backwards at 100MPH, as the question states.

The wheels will now be moving at 200MPH.

Plane speed (X) + conveyor speed (X) = tire speed (2X)

X+X=2X

Algebra. I'm teaching fucking algebra to a guy who claims to fly planes. Dear God.

Posted: 12/10/2007 10:13:34 PM EDT

[#41]

Quoted:
sniper7 is either not a pilot, or an idiot, or both. he clearly has ZERO comprehension of how an airplane propels itself, or the forces acting on an airplane in flight.

Actually, he explained it perfectly a couple pages back. He nailed it. Then after all of that, he somehow concluded that a conveyor could hold an airplane still. I'm baffled, frankly.

Posted: 12/10/2007 10:14:14 PM EDT

[#42]

Quoted:

Quoted:

The origional scenario said the conveyor keeps the airplane from moving foward...so it won't fly

No you're just adding shit to it because it never said that... It said TMC© would match the wheel speed. Big difference. But I think you already knew that.

okay, so it matches wheel speed. read my above post. conveyor matches wheel speed with engines fully spooled and no excess thrust. plane ain't going nowhere

So answer my question about the Saturn 5...

rockets do not require lift to fly. they require thrust in an excess amount that exceeds weight. the thrust to weight ratio on every single rocket is greater that 1:1
anything above 1:1 requires no lift to fly.n the only reason you see fins on them...control and stability. no lift generating required.

Posted: 12/10/2007 10:15:11 PM EDT

[#43]

Quoted:

Quoted:
OK . . . OK . . . maybe I get it.

Sniper7, you are correct. If the wheel speed matches the conveyor belt speed, there will be NO airspeed, and therefore no lift (assuming there's no wind).

What WE are arguing (and indeed, PROVING time and time again) is that while this is true in theory, it is impossible in practice to FORCE this scenario on an aircraft. You could do it, but it would be easy to get out of it. Just add a little more juice to the engines.

The only way the wheel speed matches the conveyor belt speed is if the plane is not moving. If the plane is not moving, then the conveyor belt shall not move, either.

The wheels will always move at a speed double the speed they should be going at whatever speed the plane is moving forward.

your math doesn't add up.
the wheels can be speeding at 100 knots if the conveyor is turning at 100 knots. the plane isn't moving through the air is it? the wheels do 120 and the conveyor does 120, moving yet? i think not. engines are at full thrust now and wheels are turning at 160 and the conveyor is turning at 160. the wheels have no excess speed, the engines have no excess thrust, the airplane in not moving at any speed through the air and will not fly.

Lets go back to remedial math:

Plane moves forward at 100MPH.

If plane moves forward at 100MPH, then the conveyor is moving backwards at 100MPH, as the question states.

The wheels will now be moving at 200MPH.

Plane speed (X) + conveyor speed (X) = tire speed (2X)

X+X=2X

Algebra. I'm teaching fucking algebra to a guy who claims to fly planes. Dear God.

Wait, wait, don't confuse things. If the plane is moving 100mph forward relative to the ground, and the conveyor belt is moving backwards at 100mph relative to the ground, then the wheels are moving at 200mph. But if the plane is stationary relative to the ground and the belt is moving backwards at 100mph relative to the ground, the wheels are moving at 100mph.

Posted: 12/10/2007 10:15:38 PM EDT

[#44]

Quoted:

Quoted:

The origional scenario said the conveyor keeps the airplane from moving foward...so it won't fly

No you're just adding shit to it because it never said that... It said TMC© would match the wheel speed. Big difference. But I think you already knew that.

okay, so it matches wheel speed. read my above post. conveyor matches wheel speed with engines fully spooled and no excess thrust. plane ain't going nowhere

So answer my question about the Saturn 5...

rockets do not require lift to fly. they require thrust in an excess amount that exceeds weight. the thrust to weight ratio on every single rocket is greater that 1:1
anything above 1:1 requires no lift to fly.n the only reason you see fins on them...control and stability. no lift generating required.

So, you've analyzed the question, what's the answer?

Posted: 12/10/2007 10:15:39 PM EDT

[#45]

AGNTSA

Posted: 12/10/2007 10:15:43 PM EDT

[#46]

People need to stop worring about wheel speed, ground speed and air speed. THis problem doesn't have anything to do with any of them.

Some are making the assumption that the thrust (or force) of the aircraft is equal to force of the conveyor belt. This is where the mistake creeps in. The problem statement does NOT state that the counter-rotating conveyor belt is applying a force to the airplane that is equal and opposite to the engine thrust. It simply states that the conveyor runs at a velocity inverse to the (ground) speed of the plane. The actual force transmitted to the airplane is limited to the relatively minute amount of drag due to friction in the wheel bearings (under the presumption that the pilot is not standing on the brakes). This drag force is a very tiny fraction of the forward thrust force applied by the airplane engines. In other words, the force of the belt is is defined as the wheel bearing drag, and the force of the engines thrust is far greater then the force of the wheel bearing drag. If it wasn't, or was mearly close to equal, the aircraft could never take off with or with out a conveyor belt.

Posted: 12/10/2007 10:15:48 PM EDT

[#47]

Quoted:

Quoted:
This is the problem as I recieved it in an email.

A plane is standing on a runway that can move (some sort of band conveyer). The plane moves in one direction, while the conveyer moves in the opposite direction. This conveyer has a control system that tracks the plane speed and tunes the speed of the conveyer to be exactly the same (but in the opposite direction).

The question is:

Will the plane take off or not? Will it be able to run up and take off?

I read that to mean that the conveyor belt will run at a linear speed equal to that of the aircraft. So, if the aircraft is moving at 10 mph, then the track will move at exactly 10 miles of track per hour in the other direction.

This does not mean that the aircraft is held motionless. It means that the wheels will spin at twice the RPM as they would otherwise, but the aircraft will keep on moving forward at 10mph or continue to accelerate or whatever it damn well pleases.

Now, if the problem was worded thusly

A plane is standing on a runway that can move (some sort of band conveyer). The plane moves in one direction, while the conveyer moves in the opposite direction. This conveyer has a control system that tracts the thrust of the aircraft and tunes the speed of the conveyer to be exactly that required to keep the airplane motionless by generating friction in the bearings in the landing gear system that precisely overcomes the thrust of the aircraft. We assume that the wheels, bearings and belt can all move at what ever speed needed with out failing from heat, wear etc.

The question is:

Will the plane take off or not? Will it be able to run up and take off?

With that wording, then yes, the airplane could be held stationary. Of course at that point we're suspending so much of the physics involved that it's a pretty pointless question. It might as well be about dragons and fairies on a conveyor belt.

If we use that f15 I like so much, we have to spin those bearings so fast that they generate enough friction to resist thirty thousand pounds of force. With out doing the math I can already tell you that the heat generated would immolate the bearings, wheels, landing struts, track and anything else in the vicinity. And thats assuming that the bearings, wheels and track wouldn't have long since come apart.

But, like I said, as worded, the airplane is taking off.

do the math what is +10 + -10?

0 sound right? that is your speed in your scenario. now put the engines at full throttle. without a conveyor belt, they would turn at say 160 knots. and the plane would move through the air at 160 knots.

now, add the conveyor to the equation. the conveyor is working at -160 knots.

what is +160 + -160?

0 sound right? that is the speed through the air of the airplane. the wheels are doing 160 knots, the conveyor is doing 160 knots in the opposite direction. the engines have no more thrust. the airspeed is 0. the amount of air passing over the wing is 0. the amount of lift that is generated is 0. the airplane won't fly.

and since the plane isn't pushed on the ground by powering the wheels, what difference does any of this make?

Posted: 12/10/2007 10:16:03 PM EDT

[#48]

Quoted:

do the math what is +10 + -10?
0 sound right? that is your speed in your scenario. now put the engines at full throttle. without a conveyor belt, they would turn at say 160 knots. and the plane would move through the air at 160 knots.

now, add the conveyor to the equation. the conveyor is working at -160 knots.

what is +160 + -160?

0 sound right? that is the speed through the air of the airplane. the wheels are doing 160 knots, the conveyor is doing 160 knots in the opposite direction. the engines have no more thrust. the airspeed is 0. the amount of air passing over the wing is 0. the amount of lift that is generated is 0. the airplane won't fly.

Can you pretty please explain what a negative speed is? I'd love to hear this.

Posted: 12/10/2007 10:16:11 PM EDT

[#49]

Quoted:

Quoted:
OK . . . OK . . . maybe I get it.

Sniper7, you are correct. If the wheel speed matches the conveyor belt speed, there will be NO airspeed, and therefore no lift (assuming there's no wind).

What WE are arguing (and indeed, PROVING time and time again) is that while this is true in theory, it is impossible in practice.

Now you are going backwards...

Huh?

It is true that if the belt speed matches the wheel speed, the plane will be stationary.

But that's as far as it goes.

God Damnit....NO!!!! The belt speed will ALWAYS match the wheel speed...ALWAYS. but whether the two are turning at 10 knots or 1000 has nothing to do with the engines pushing the plane through the air.

You only partially get it. the engines push air. while in *flight* the engines push the airplane through the air. while on the ground, the engine push the airplane through the air but rotate the wheels at the same time due to their ability to drasticall reduce the drag and the amount of thrust necessary for the airplane to reach the airspeed necessary for flight.

Posted: 12/10/2007 10:16:32 PM EDT

[#50]

WHAT DO THE ENGINES ACT ON

jesus tittyfucking christ! the engines do not act on the treadmill in any way shape or form. they act on the AIR, which is not acted on by the treadmill.

The treadmill is merely a distractor to trap RETARDS who can't disconnect the wheel from a means of propulsion.

What if the airplane was on floats and was on a river? What if it was on skis and was on snow? THE SAME THING WOULD HAPPEN! The engines would overcome the negligible drag of whatever surface it was on by PULLING THE AIRPLANE THROUGH THE AIR and it would lift off every time.

[ARCHIVED THREAD] - The OFFICIAL will the conveyor belt plane fly thread!!!! **UPDATE FIRST POST*** (Page 5 of 20)

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